WASHINGTON — A documentary about the historic water contamination at the Marines' Camp Lejeune, N.C., will have its world premiere this spring at the Tribeca Film Festival in New York.

"Semper Fi: Always Faithful" tracks the evolution of Marine veteran Jerry Ensminger into an environmentalist after his young daughter, Janey, died of leukemia in 1985.

Ensminger, a former drill instructor from White Lake, N.C., helped uncover voluminous details about the extent of contamination that poisoned the drinking water at Marine Corps Base Camp Lejeune for decades. A million people are thought to have been exposed to the water. Thousands, like Ensminger, suspect that the poisons caused the illnesses that they and their family members have suffered.

The movie's directors, Rachel Libert and Tony Hardmon, have spent at least two years working on the film.

Tribeca announced Monday that "Semper Fi" will be among a dozen films in its world documentary competition. The movie festival takes place from April 20 to May 1.